Catheter system with attachable catheter hub

ABSTRACT

A hemodialysis catheter assembly adapted for use in a subcutaneous tunneling procedure incorporates a mechanism for securing the catheter hub member to the elongated catheter, and to provide the requisite fluid communication between fluid passages within the hub and the catheter lumens within the catheter. The catheter hub member may be connected to the elongated catheter after implantation of the catheter via a subcutaneous tunneling procedure.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 60/904,459, filed Mar. 2, 2007.

BACKGROUND

1. Technical Field

The present disclosure is directed to a catheter assembly, and, in particular, relates to a catheter system adapted for use in a subcutaneous tunneling catheterization procedure. The present disclosure further relates to catheter hubs or housing mechanisms which are selectively attachable to an elongated catheter tube either prior, to or subsequent to, implantation of the catheter tube during a hemodialysis procedure.

2. Description of the Related Art

Catheters are flexible medical instruments intended for the withdrawal and introduction of fluids relative to body cavities, ducts, and vessels. Catheter instrumentation may have particular application in a hemodialysis procedure where blood is withdrawn from a blood vessel for treatment, and subsequently returned to the blood vessel for circulation. Known hemodialysis catheters include multiple lumens, such as dual lumen or triple-lumen catheters, permitting bi-directional fluid flow within the catheter whereby one lumen is dedicated for withdrawal of blood and the other lumen is dedicated for returning the treated blood to the vessel. During an exemplary hemodialysis procedure, a multiple lumen catheter is inserted into a body and blood is withdrawn through an arterial lumen of the catheter. The removed blood is directed to a hemodialysis unit which dialyzes, or purifies, the blood to remove waste, and toxins. The dialyzed blood is returned to the patient through a venous lumen of the catheter.

Various techniques are employed for the insertion of hemodialysis catheters including, e.g., with the use of guidewires, introduction stylets or the like. Some of these known techniques include subcutaneous tunneling methodologies where a subcutaneous tunnel is formed between two spaced openings in the skin with the use of a trocar or the like. One catheter end is introduced through an entry site or venotomy site for routing into, e.g., the jugular vein and routed to the heart. The trailing or proximal end is advanced through the subcutaneous tissue to exit a second exit opening adjacent the sternum of the patient beneath the venotomy site. Once the proximal end of the catheter is exposed, a catheter hub with extension tubes is fluidly connected to the catheter. One subcutaneous technique is disclosed in U.S. Pat. No. 5,509,897 to Twardowski et al., the contents of which is incorporated herein by its entirety.

SUMMARY

Accordingly, the present disclosure is directed to a hemodialysis catheter assembly adapted for use in a subcutaneous tunneling procedure. Various embodiments of the hemodialysis catheter assembly are disclosed. Each embodiment of the catheter assembly incorporates a mechanism for securing the catheter hub member to the elongated catheter, and to provide the requisite fluid communication between fluid passages within the hub and the catheter lumens within the catheter. The catheter hub member may be connected to the elongated catheter after implantation of the catheter via a subcutaneous tunneling procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the disclosure will be better understood with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of the catheter system in accordance with the principles of the present disclosure illustrating the attachable catheter hub and the elongate catheter member;

FIG. 2 is a cross-sectional view taken along the lines 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. 2;

FIG. 4 is a perspective view with parts separated illustrating the components of the catheter system of FIG. 1;

FIG. 5 is a perspective view an alternate embodiment of the catheter system;

FIG. 6 is a cross-sectional view taken along the lines 6-6 of FIG. 5;

FIG. 7 is a perspective view with parts separated illustrating the components of the catheter system of FIG. 5;

FIG. 8 is a perspective view an alternate embodiment of the catheter system;

FIG. 9 is a perspective view with parts separated illustrating the components of the catheter system of FIG. 8;

FIG. 10 is a perspective view an alternate embodiment of the catheter system;

FIG. 11 is a perspective view with parts separated illustrating the components of the catheter system of FIG. 10;

FIG. 12 is a perspective view with parts separated of an alternate embodiment of the catheter system of FIG. 10 incorporating a metal locking ring;

FIG. 12A is a side cross-sectional view of the catheter system of FIG. 12;

FIG. 12B is a perspective view of an alternate embodiment of the catheter system of FIG. 12;

FIG. 13 is a perspective view of the metal locking ring of FIG. 12;

FIG. 14 is a perspective view of an alternate embodiment of the catheter system illustrating the catheter hub;

FIG. 15 is a perspective view with parts separated of the catheter system of FIG. 14;

FIG. 16 is a side cross-sectional view of the catheter hub of FIGS. 14-15;

FIG. 17 is a perspective view of another alternate embodiment of the catheter system;

FIG. 18 is a view similar to the view of FIG. 17 with portions cut away to illustrate the internal components of the catheter system;

FIG. 19 is a side cross-sectional view of the catheter hub of the catheter system of FIGS. 17-18;

FIG. 20 is a perspective view of another alternate embodiment of the catheter system;

FIG. 21 is a perspective view with parts separated of the catheter system of FIG. 20;

FIG. 22 is a side cross-sectional view of the catheter hub of the catheter system of FIGS. 20-21;

FIG. 23 is a perspective view with parts separated of a catheter hub of another embodiment of the catheter system;

FIG. 24 is an enlarged perspective view of the connector tubes and threaded collar of the catheter hub of FIG. 23;

FIG. 25 is a side cross-sectional view of the catheter hub of FIG. 23 illustrating the securing of the catheter member;

FIG. 26 is a view of an alternate embodiment of the catheter hub of FIG. 23;

FIG. 27 is a perspective view of another alternate embodiment of the catheter system;

FIG. 28 is a perspective view with parts separated of the catheter system of FIG. 27;

FIG. 29 is a side cross-sectional view of the catheter hub of FIG. 27 illustrating the securing of the catheter member;

FIG. 29A is a side cross-sectional view of an alternate embodiment of the catheter system;

FIG. 29B is a side cross-sectional view of an alternate embodiment of the catheter system;

FIG. 29C is a side cross-sectional view of an alternate embodiment of the catheter system;

FIG. 29D is a side cross-sectional view of the catheter hub of FIG. 29C separated from the catheter;

FIG. 29E is a side cross-sectional view of the catheter hub of FIG. 29C coupled to the catheter;

FIG. 30 is a side cross-sectional view of a catheter hub of another embodiment of the catheter system.

FIG. 31 is a perspective view of an alternate embodiment of a catheter system;

FIG. 32 is a perspective view of the catheter hub of the embodiment of FIG. 31 in an open position;

FIG. 33 is a perspective view illustrating the interior of the catheter hub with a catheter member; and

FIG. 34 is a view illustrating closing of the catheter hub about the catheter; and

FIG. 35 is a view of a subcutaneous procedure in which the catheters systems may be used.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The exemplary embodiments of the catheter systems and methods of use disclosed are discussed in terms of medical catheters for the administration of fluids (withdrawal or introduction) relative to the body of a subject and, more particularly, in terms of a hemodialysis catheter. However, it is envisioned that the present disclosure may be employed with a range of catheter applications including surgical, diagnostic and related treatments of diseases and body ailments of a subject. It is further envisioned that the principles relating to the catheter disclosed include employment with various catheter related procedures, such as, for example, hemodialysis, cardiac, abdominal, urinary, intestinal, and in chronic and acute applications. Moreover, the catheter can be used for administration of fluids such as, for example, medication, saline, bodily fluids, blood and urine.

In the discussion that follows, the term “proximal” or “trailing” will refer to the portion of a structure that is closer to a clinician, while the term “distal” or “leading” will refer to the portion that is further from the clinician. As used herein, the term “subject” refers to a human patient or other animal. The term “clinician” refers to a doctor, nurse or other care provider and may include support personnel.

The following discussion includes a description of the catheter system, followed by a description of an exemplary method of operating the catheter in accordance with the principles of the present disclosure. For discussion purposes, the catheter will be discussed in terms of a hemodialysis catheter and the method of operation will be discussed in terms of a reverse tunneling procedure utilized for positioning the catheter during a dialysis procedure. However, those skilled in the art will appreciate the catheter has many other applications in addition to dialysis applications.

Referring now to the FIGURES wherein like components are designated by like reference numerals throughout the several views, FIGS. 1-4 illustrate in perspective views, the hemodialysis catheter 10 in accordance with the principles of the system of the present disclosure. Catheter 10 includes several components assembled together, namely, catheter hub or housing 12 and elongated catheter tube or member 14 extending distally from the catheter hub 12. In general, catheter hub 12 is attachable to catheter member 14 subsequent to implantation of the catheter member 14 relative to the patient during a medical procedure such as, e.g., a hemodialysis procedure. Various mechanisms for attaching catheter hub 12 to catheter tube are contemplated by the present disclosure and will be described in greater detail hereinbelow.

Catheter hub 12 is advantageously dimensioned for engagement by the clinician. Catheter hub 12 includes proximal or trailing housing section 18 and distal or leading housing section 20 adjacent catheter members 14. Trailing housing section 18 is connectable to extension tubes (not shown) through extension tube mounts 15, which serve as the venous and arterial lines leading to the hemodialysis machine as is conventional. Leading housing section 20 defines an annular collar 22. Annular collar 22 has internal lumens 23 in fluid communication with fluid passages 25 extending through catheter hub 12. Internal lumens 23 may be generally D-shaped. Other configurations are also envisioned. Annular collar 22 may be formed of a compressible material. Catheter hub 12 may further include a pair of opposed suture wings 24 along its outer surface. Suture wings 24 define openings 26 dimensioned for receiving sutures which may be utilized in securing catheter hub 12 relative to the subject. In an alternative embodiment, catheter hub 12 may have an annular groove (not shown) in its outer wall in lieu of suture wings 24. A suture may be wrapped within annular groove and subsequently secured relative to the subject.

Catheter member 14 may be any catheter tube suitable for use with a desired medical procedure. Catheter member 14 may be single, dual or triple lumen catheters. In the embodiment shown in FIG. 1, catheter member 14 is a dual lumen catheter having particular application in a hemodialysis procedure. However, catheter member 14 may be any commercial available catheter member such as the catheter members sold under the trademarks Palindrome and Mahurkar. In this regard, catheter member 14 has first and second longitudinal lumens 28, 30 separated by a septum wall 32 which extends the length the catheter tube. Each of the first and second longitudinal lumens 28, 30 may define a D-shaped opening in cross-section. Other lumen arrangements are also envisioned including circular, pie shaped or other shapes known in the art. Coaxial lumens are also envisioned. Leading or distal end 34 of catheter member 14 may have various configurations. In one embodiment, the arrangement of catheter distal end 34 is similar to an embodiment disclosed in commonly assigned U.S. Patent Publication No. 2005/0267400 to Haarala et al., filed Feb. 11, 2005, the entire contents of which is incorporated herein by reference. Other arrangements, e.g., as disclosed as alternate embodiments in the Haarala '400 publication, are also envisioned.

Catheter member 14 is preferably flexible and may be formed by conventional injection molding or extrusion means. The wall of catheter member 14 may include reinforcing material if desired. Catheter member 14 may have a pre-curved configuration in its normal state, i.e., have a preformed bend which it normally assumes in the absence of an external stressor to conform to a body cavity or vessel in which the catheter member is to be positioned. Alternatively, catheter member 14 may be devoid of any normally curved orientation.

Referring still to FIGS. 14, hub attachment mechanism will be discussed. Hub attachment mechanism 36 includes multiple tube connector 38 and at least one, preferably, two locking collars 40. Multiple tube connector includes two connector tubes 42 and connector collar 44. Connector collar 44 includes two openings therethrough which accommodate connector tubes and maintains the connector tubes 42 in side by side but slightly spaced relation. Connector collar 44 may be secured to connector tubes 42 if desired. Connector tubes 42 each define a cross-section which generally approximates the cross-section of lumens of catheter member 14 and internal passages within catheter hub 12. In one embodiment, the cross-section of connector tube is generally D-shaped to at least correspond to the D-shaped arrangement of catheter member.

Locking collars 40 are each split into two substantially equal half rings 40 a, 40 b. Means for connecting half rings are envisioned. In one embodiment, one half ring 40 a of locking collar 40 includes at least one locking projection 46 which is receivable in a corresponding recess(es) 48 of the opposed locking ring 40 b in snap relation to secure the half rings together. Other means for securing half rings 40 a,40 b are also envisioned including with the use of cements, adhesives, tongue-groove arrangement or the like. Half rings 40 a,40 b of locking collars 40 may be connected together through a hinge or the like or connected by a tether.

Upon assembly of catheter hub 12 to catheter member 14 when, e.g., catheter member 14 is appropriately positioned relative to the body, connector tube assembly 38 is first positioned within catheter member 14 with catheter tube ends of the first and second tubes 42 being received within respective lumens of the catheter. Preferably, proximal end of catheter member 14 is advanced along catheter tube ends until the proximal face of catheter contacts connector collar 44. Similarly, hub tube ends of connector tubes 42 are positioned within internal passages of catheter hub 12 and the catheter hub 12 is advanced along the catheter tube ends. Thereafter, half rings 40 a,40 b of one locking collar 40 are positioned about proximal end 14 p of catheter member 14 and the half rings 40 a,40 b of the second collar 40 are positioned about hub mounting collar 22 of catheter hub 14. Each of respective half rings 40 a,40 b is snapped together to the condition depicted in FIG. 1. In this position, locking collar 40 compresses proximal end 14 p of catheter member 14 against catheter tube ends of connector tubes 42 and locking collar 40 compresses mounting collar 22 of catheter hub 12 against hub tube ends of connector tubes 42. With this arrangement, a compressive frictional relationship is established between locking collars 40 and respective proximal end 14 p of catheter tube 14 and hub mounting collar 22 to thereby secure catheter member 14 and catheter hub 12 to connector assembly 38 and attaching catheter hub 12 to catheter member 14. It is also envisioned that half rings 40 a, 40 b of locking collars 40 may be integrally, or monolithically, formed as a single unit resembling a clam shell arrangement. Half rings 40 a, 40 b could fold along hinges to assume the locked position around catheter hub 12 and catheter member 14.

FIGS. 5-7 illustrate an alternate embodiment of the hub attachment mechanism of FIGS. 1-4. In accordance with this embodiment, locking collars are replaced with single elongate locking sleeve which is coaxially positionable about the proximal end of catheter member. Connector assembly is similar to the connector assembly of FIGS. 1-4, with connector tubes being positioned within lumens of catheter member and passages of catheter hub 12 in the manner discussed hereinabove. Locking sleeve 50 is fabricated from a suitable elastomeric material such that it may stretch when positioned over the proximal end 14 p of catheter member 14 and hub mounting collar 22 of catheter hub 12. Locking sleeve 50 is advanced in a proximal direction toward catheter hub 12 which causes internal surfaces 52 of locking sleeve 50 to compress the proximal end 14 p of catheter member 14 against connector tube end in frictional relation therewith. In one embodiment, the internal bore of locking sleeve 50 is less in dimension or diameter than the cross-sectional dimension of connector ends of connector tubes 42 requiring the locking sleeve 50 to stretch over the connector tubes 42. The proximal end of locking sleeve 50 is continually advance toward catheter hub 12 to be positioned about peripheral ribs 54 of the catheter hub 12. Peripheral ribs 54 also serve to secure locking sleeve 50 to catheter hub 12. As best depicted in FIG. 6, locking sleeve 50 may compress the proximal end 14 p of catheter member 14 tube and/or hub mounting collar 22 to secure connector tubes 42, catheter member 14 and catheter hub 12. Connector tubes 42 may also possess raised protrusions 58 on its outer surface on both connector end and hub end of the tubes 42 to facilitate the frictional relationship between the components. The elastomeric characteristics of locking collar 50 may facilitate the establishment of a seal about the catheter member.

FIGS. 8-9 illustrates another embodiment of catheter system. In accordance with this embodiment, an elastomeric grommet 60 is mounted or molded about connector tubes 42. The elastomeric grommet 60 includes first collar segment 60 a and second collar segment 60 b. First collar segment 60 a defines a cross-sectional dimension that is greater than the cross-sectional dimension of second collar segment 60 b. Connector tubes 42 are positioned within the catheter hub 12 and catheter member 14 is mounted about the connector tubes 42 and advanced to the collar or grommet 60. Catheter hub 12 includes mounting collar 62 having an external threaded portion 64. Collar segment 60 b of the elastomeric grommet 60 is dimensioned for reception within an internal bore 63 of mounting collar 62. Second collar segment 60 b engages the internal surfaces of mounting collar 62 and may create a seal therein. Locking sleeve 66 incorporates corresponding internal threaded 68 (shown in cut-away) adjacent its proximal end. Once connector assembly is positioned with respect to lumens of catheter member 14 and internal passages of catheter hub 12, locking sleeve 66 and catheter member 14 are advanced toward catheter hub 12 to approximate locking sleeve 66 and mounting collar 62 of the catheter hub 12. Thereafter, locking sleeve 66 is rotated whereby the corresponding threaded components 64, 68 of locking sleeve 66 and mounting collar 62 cooperate to secure the locking sleeve 66 to catheter hub 12. Locking sleeve 66 may have an internal dimension to compress elastomeric first collar segment 60 a of grommet 60 thereby creating an interference relationship between the locking sleeve 66 and connector tubes 42 and also facilitating the formation of a seal within catheter hub 12.

FIGS. 10-11 illustrate another embodiment of the present disclosure. In accordance with this embodiment, catheter hub 70 incorporates mounting collar 72 which possesses first and second longitudinal grooves 74 arranged in opposed relation. Catheter hub 70 also incorporates first and second hypo tubes 76 which may be fixed within the catheter hub 70. Locking sleeve 78 mounted about catheter member 14 incorporates first and second axially depending locking tabs 80. Locking tabs 80 each incorporate locking detents 82. Upon assembly, locking tabs 80 are positioned within first and second longitudinal grooves 74 of catheter hub 70 with locking detents 82 of the locking tabs 80 securely engaging proximally facing shelves 84 of mounting collar 72 to secure locking sleeve 78 and catheter hub 70. Locking sleeve 78 may incorporate internal structure to compress the proximal end of catheter 14 against the hypo tubes. Alternatively, the lumens of catheter member 14 may be dimensioned to form a friction fit about the hypo tubes 76. Locking sleeve 78 and/or locking tabs 80 may be rigid such that securement of the locking tabs 80 to the catheter hub 70 may be irreversible. This may prevent disconnection by the patient.

FIGS. 12, 12A and 13 illustrate another embodiment generally similar to the embodiment of FIGS. 10-11. However in accordance with this embodiment, a compressible member or ring 90 is positioned about the proximal end of catheter member 14 prior to securement of locking sleeve 78. Compressible ring 90 is preferably made of spring metal or the like and has a plurality of radially spaced deflectable elements 91. Each deflectable element 91 has edge 92 which may engage the proximal end of catheter member 14 to assist in securing catheter member 14 to the hypo tubes 76. Compressible ring 90 is deflected inwardly during securement of locking sleeve 78 to catheter hub 12 as best depicted in FIG. 12A through engagement of outer ramp surfaces 94 of the deflectable elements 91 and the interior of locking sleeve 78.

FIG. 12B shows an alternate embodiment with a deflecting ring 93 positioned around the proximal end of the catheter 14. The deflecting ring 93 compresses and seals the catheter 14 once locking sleeve 78 is advanced in a proximal direction toward the catheter hub 70. The radial compression exerted by the deflecting ring 93 on the catheter 14 grips the catheter 14 to the first and second hypo tubes 76, thereby retaining the catheter 14 connected to the catheter hub 70. Deflecting ring 93 includes ring collar 93 a and compressing segment 93 b extending from the ring collar 93 a. Compressing segment 93 b includes axial slots 93 c which permit inward deflection of the compressing segment 93 b. Ring collar 93 a may have a recess 93 d for receiving a corresponding tab 72 a of mounting collar 72 of catheter hub 70. This arrangement may facilitate securement of deflecting ring 93 relative to catheter hub 70.

FIGS. 14-16 illustrate another embodiment of the catheter hub attachment mechanism. In accordance with this embodiment, hypo tubes or connector tubes 90 are mounted to extend from catheter hub 92. Catheter member 14 is advanced over the connector or hypo tubes 90 to essentially abut against the distal face of catheter hub 92. Locking sleeve 94 is pushed or advanced over the proximal end 14 p of catheter member 14 whereby locking detent 96 of the locking sleeve 94 engages corresponding annular ridge 98 of catheter hub 92 to secure the locking sleeve 94 to the catheter hub 92. As a further feature, the internal surface of locking sleeve 94 may incorporate interference areas 100 which extend radially inwardly. The interference areas 100 serve to compressibly engage the outer surface of catheter member 14 to establish an interference relation therewith. Locking sleeve 94 may be formed of a suitable elastomeric material to expand and contract to permit positioning over catheter hub.

FIGS. 17-19 illustrate another embodiment of the hub attachment mechanism. Catheter hub 110 includes tapered mounting collar 112 and annular shelf 114 adjacent a proximal end of the mounting collar 112. Locking sleeve 116 incorporates several components which permit releasable attachment of locking sleeve 116 to catheter hub 110. Specifically, locking sleeve 116 includes outer locking member 118 and inner locking member 120. Outer member 118 may be elastomeric and encloses inner member 120 and the proximal end 14 p of catheter member 14. Outer member 118 may have an internal annular detent 122 at its trailing end which is received within a corresponding outer annular recess 124 of catheter hub 110 to secure the outer member 120 to the catheter hub 110. Inner member 112 includes opposed locking legs 124 which are interconnected by partial ring 126 extending between the legs 124. Locking legs 124 are adapted for pivotal movement relative to rings 126 upon depression of leading leg elements 124 l. This action will cause trailing leg elements 124 t to pivot radially outwardly out of engagement with corresponding locking recesses 128 in mounting collar 112 of catheter hub 110. In use, catheter member 14 is positioned about the hypo or connecting tubes extending from catheter hub 112. Thereafter, locking sleeve 116 is advanced to resiliently and/or frictionally engage the outer surface of catheter member 14. When appropriately positioned, trailing or proximal leg elements 124 t are positioned whereby locking detents 130 of the leg elements are received within locking recesses 128 of mounting collar 120. Similarly, internal annular detent 122 of outer member 118 is secured within annular recess 124 of catheter hub 110. With this arrangement, locking sleeve 116 and catheter member 14 are secured to catheter hub 110. When it is desired to release catheter hub 110 from catheter member 14, outer member 118 is depressed adjacent finger grooves 134 which causes engagement with the leading or distal leg elements 124 l of locking legs 124. Further squeezing movement causes, proximal or trailing leg elements 124 t to pivot outwardly and become released from locking recesses 128. Catheter member 14 may then be moved from catheter hub 110.

FIGS. 20-22 illustrate another alternate embodiment of the catheter hub attachment mechanism. In accordance with this embodiment, locking sleeve 150 includes first 152 and second series 154 of internal threads. The first series 152 is adapted to threadably engage the outer threaded surface 156 of mounting collar of catheter hub 158. The second series 154 engages the proximal end of catheter tube 14 when the locking sleeve 150 is secured to the catheter hub 158. In one aspect of this embodiment, hypo tubes 160 extending from catheter hub 158 may be slightly larger in diameter or dimension than internal lumens of the catheter 14. Thus upon passage of the catheter proximal end 14 p over the respective hypo tubes 160, the catheter must stretch to some degree to accommodate the hypo tubes 160. Thus upon securing of locking sleeve 150, the second series of threads 154 more readily bites into the catheter proximal end 14 p securing the catheter 14 relative to the hypo tubes and the hub.

FIGS. 23-25 illustrate another embodiment which is substantially similar to the prior embodiment. In accordance with this embodiment, however, the connection tubes or hypo tubes define a dimension which increases in cross section toward catheter hub, i.e., has an outward flare adjacent catheter hub. This configuration may facilitate initial positioning of proximal catheter end onto the connection tubes whereby upon continued movement toward catheter hub, the wider dimension of the hypo tubes contacts the proximal end of the catheter, e.g., in frictional engagement therewith. In addition, upon tightening of locking sleeve, the internal threads in effect obtain a larger bite of the catheter adjacent catheter hub at the flared areas further securing the catheter on the hub.

FIG. 26 has an alternate embodiment of catheter hub which may be utilized with the embodiments of FIGS. 20-25. In this embodiment, instead of the hypo tubes having a flared aspect, catheter hub incorporates flared areas or molded projections 180 extending from hub mounting collar. Thus upon advancement of catheter proximal end, the proximal end will widen adjacent catheter hub. This enables locking sleeve, e.g., the second series of threads 154 to engage the catheter at the extreme proximal end adjacent the hub mounting collar.

FIG. 27-29 illustrate an alternate embodiment where locking sleeve 200 includes two interconnected components, namely, distal elastomeric component 202 and relatively rigid proximal component 204. Rigid component 204 incorporates opposed locking tabs 206 and detents 208 receivable within locking grooves 210 of catheter hub in a similar manner to the embodiment of FIG. 11. Elastomeric component 202 is adapted to form a seal about catheter member adjacent the extreme distal or leading end of the elastomeric component. The seal may incorporate a radially inwardly directed annular projection 214 or the like. The seal may minimize the passage of fluids through locking sleeve.

FIG. 29A illustrates an alternate embodiment incorporating O-ring 203. As locking sleeve 200 advances proximally over the first and second hypo tubes 205, 207, the locking sleeve 200 radially compresses the O-ring 203 between an internal shelf 200S of the locking sleeve and the distal or leading face 112 a of catheter hub 110. The compressed O-ring 203 secures catheter 14 to catheter hub 110. O-ring 203 may be made of soft material, an elastomer, a rigid material, or any other suitable material. In an alternate embodiment depicted in FIG. 29B, internal shelf 200 S of locking sleeve 200 is adjacent the distal or leading end of the locking sleeve 200.

FIG. 29C depicts an alternative embodiment of the locking sleeve 200. In this embodiment, locking sleeve 200 includes a housing 209 extending distally therefrom. The housing 209 incorporates rigid detents 211 adapted to compress the catheter 14 against the hypo tubes 205, 207. Rigid detents 211 are biased inwardly with respect to the catheter 14. The radial compression exerted by the rigid detents 211 secures the catheter 14 to the catheter hub. The housing 209 may include radial gaps to facilitate assembly and enhance grip. Additionally, the housing 209 may be clear to facilitate visualization of the position of the catheter 14 when the catheter 14 is advanced toward the catheter hub. As illustrated in FIGS. 29D and 29E, the housing 209 of locking sleeve 200 may further include an adhesive 213 therein. The adhesive 213 attaches the catheter 14 to the locking sleeve 200 and may compress the catheter 14 to form a fluid tight seal. After the proximal end of the catheter 14 is positioned within the housing 209, the adhesive 213 seals and attaches catheter 14 to the catheter hub. At the same time, the rigid detents 211 of the housing 209 compress the catheter 14 against the hypo tubes 205, 207, thereby securing the catheter 14 to the catheter hub. Adhesive 213 may be any suitable kind of adhesive including, but not limited to, an adhesive hydrogel.

FIG. 30 illustrates an alternate embodiment where locking sleeve 220 and hypo tubes 222 have a similar sloped, angled or arcuate surface 224, 226. This angled surface may enhance the interference relationship of the locking sleeve 220 with t the catheter tube.

FIGS. 31-34 illustrate another catheter hub 170 consisting of two half shells 172 connected to each other through a hinge 174. The interior of the catheter hub 170 has arcuate recesses 176 which capture an outer ring 178 attached to the proximal end 14 p of the catheter 14. In use, the proximal catheter end 14 p is positioned within the open catheter hub 170 with the ring 178 seated within one recess 176 of the half shell. The other half shell is folded onto the half shell and can be connected thereto via a snap fit or the like such as the pin and hole 180, 182 arrangement shown. With the catheter ring 178 secured within the recess 176 of the catheter hub 170 the catheter is thereby secured to the hub 170.

The use of any of the aforementioned catheter systems will now be discussed in connection with a subcutaneous tunneling procedure for hemodialysis. With reference to FIG. 35, the leading or distal end of the catheter may be implanted within a major vein of a patient via the reverse tunneling method disclosed in U.S. Pat. No. 5,509,897 to Twardowski, the entire contents of the '897 patent being incorporated herein by reference. In accordance with one embodiment of this procedure disclosed in the '897 patent, a catheter 14 is positioned through an incision “i” made beneath the clavicle, and advanced to enter the right atrium “ra”. A surgical tunnel is then created from the initial incision “i” outwardly to an exit site “e” remote from the original incision “i”. Alternatively, the surgical tunnel may be created from the exit site “e” to the initial incision “i.” A proximal section 14 p of the catheter 14 is advanced through the tunnel and out through the exit site “e”. With the proximal end of the catheter exposed, any of the aforementioned hub attachments mechanisms may be employed to attach the catheter hub to the catheter. Thereafter, the venous and arterial lines are connected to the catheter hub as is conventional.

Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure. 

1. A hemodialysis catheter assembly, which comprises: a catheter hub member defining a passage for passage of fluids, the catheter hub member including a mounting collar defining an internal bore in fluid communication with the passage; an elongated catheter including a catheter lumen extending along at least a portion of a length thereof; and a hub attachment mechanism for releasably connecting the catheter to the catheter hub, the hub attachment mechanism including: a tube connector having a first connector end for insertion within the internal bore of the catheter hub member and a second connector end for insertion within the catheter lumen of the catheter; and at least one locking member positionable about the second connector end of the tube connector when the second connector end is inserted within the catheter lumen of the catheter, the at least one locking member adapted to compress the catheter against the second connector end of the tube connector to thereby secure the catheter to the tube connector.
 2. The catheter assembly according to claim 1 wherein the at least one locking member is positionable about the first connector end of the tube connector when the first connector end is inserted within the internal bore of the mounting collar of the catheter hub member, the at least one locking member adapted to compress the mounting collar against the first connector end of the tube connector to thereby secure the catheter hub member to the tube connector.
 3. The catheter assembly according to claim 1 wherein the hub attachment mechanism includes first and second tube connectors, each tube connector having the first and second connector ends for respective reception within a pair of internal bores of the mounting collar and a pair of catheter lumens of the catheter.
 4. The catheter assembly according to claim 3 wherein the at least one locking member of the hub attachment mechanism includes first and second locking collars, the first locking collar being positionable about the first connector ends of the tube connectors and the second locking collar being positionable about the second connector ends of the tube connectors.
 5. The catheter assembly according to claim 4 wherein each locking collar includes a first collar segment and a second segment collar segment, the first and second collar segments being releasably attachable to each other.
 6. The catheter assembly according to claim 4 further including a connector collar defining first and second openings for receiving the first and second connector tubes and adapted to maintain the first and second connector tubes at a predetermined relation.
 7. The catheter assembly according to claim 3, wherein the at least one locking member of the hub attachment mechanism includes a second locking collar, the locking collar including first and second portions pivotally coupled to each other, the locking collar being positionable about either the first or second connector ends of the tube connectors.
 8. The catheter assembly according to claim 1 wherein the at least one locking member of the hub attachment mechanism includes a locking sleeve, the locking sleeve adapted to be positioned about the first and second connector ends of the tube connector.
 9. The catheter assembly according to claim 8 wherein the locking sleeve is adapted to compress the mounting collar against the first connector end of the tube connector to thereby secure the catheter hub member to the tube connector.
 10. The catheter assembly according to claim 9 wherein the locking sleeve comprises an elastomeric material.
 11. The catheter assembly according to claim 8 including a compressible grommet positioned about the second connector end of the tube connector.
 12. The catheter assembly according to claim 11 wherein the locking sleeve includes a threaded portion and the mounting collar of the catheter hub member includes a corresponding threaded portion, the threaded portions cooperating to secure the locking sleeve relative to the catheter hub member.
 13. A hemodialysis catheter assembly, which comprises: a catheter hub member including a mount having opposed longitudinal external grooves, the external grooves defining locking shelves within the catheter hub member; first and second tubes extending from the catheter hub member for passage of fluids; an elongated catheter including first and second catheter lumens, and defining leading and trailing ends, the elongated catheter mountable to the catheter hub member with the first and second tubes received within the first and second catheter lumens at the trailing end of the catheter; and a locking sleeve slidably mounted relative to the catheter, the locking sleeve including a pair of locking tabs with locking detents, the locking tabs being adapted for reception within the external grooves with the locking detents engaging the locking shelves to thereby secure the locking sleeve to the catheter hub member.
 14. The catheter assembly in accordance to claim 13 further comprising a compressible ring positioned within the locking sleeve, the compressible ring adapted to compress the catheter against the tubes during securement of the locking sleeve to the catheter hub member.
 15. The catheter assembly in accordance to claim 14, wherein the compressible ring includes a plurality of deflectable elements arranged in radial spaced relation, the deflectable elements being deflected inwardly during securement of the locking sleeve to the catheter hub member, to thereby engage the trailing end of the catheter.
 16. A hemodialysis catheter assembly, which comprises: a catheter hub member including a mounting collar defining an external thread; first and second tubes extending from the catheter hub member for passage of fluids; an elongated catheter including first and second catheter lumens, and defining leading and trailing ends, the elongated catheter mountable to the catheter hub member with the first and second tubes received within the first and second catheter lumens at the trailing end of the catheter; and a locking sleeve slidably mounted relative to the catheter, the locking sleeve defining a first internal thread and a second internal thread, the first internal thread being adapted to mate with the external thread of the catheter hub member, the second internal thread being adapted to engage the trailing end of the catheter to thereby secure the catheter to the catheter hub member.
 17. A hemodialysis catheter assembly, which comprises: a catheter hub member including first and second shell members, the first shell member and the second shell member being operatively connected to each other and adapted for relative movement between a first open position and a second closed position, the first and second shell members defining an internal annular recess when in the second closed position; an elongated catheter defining at least one longitudinal lumen and having leading and trailing ends, the catheter having an external locking ring adjacent the trailing end thereof; whereby the trailing end of the catheter is positionable within the first and second shell members when in the first open position thereof and whereby the external locking ring is securely received within the internal annular recess of the first and second shell members when in the second closed position to thereby secure the catheter to the catheter hub member. 